Card telephone dialing machine

ABSTRACT

In a telephone dialing device the punched card is not driven through a chute but is dropped through a substantially vertical chute. An electromagnetically operated plunger intermittently arrests the card in the chute, causing the card to drop through the chute in a series of steps. Photoelectric cells sense successive rows of holes in the card as the card drops in successive steps through the chute to control the transmission of dialing code signals.

United States Patent Ronald George Lane Billingshurst, Sussex, England 780,104

Nov. 29, 1968 July 13, 1971 Sontranic Limited Edgware, Middlesex, England Feb. 26, 1968 Great Britain [72] inventor Appl. No. Filed Patented Assignee Priority CARD TELEPHONE nuuuc MACHINE 9 Claims, 2 Drawing Figs.

u.s. Cl 179/90 rm. Cl H04m l/48 FieldofSearch l79/9OCI, 9OADO,5;235/61.ll B,6l.ll D.6l.ll A

OOOQOOQOOQOQ [56] References Cited UNITED STATES PATENTS 2,966,557 12/1960 Schmitt 179/90 2,505,069 4/1950 Savino l79/90 Primary Examiner-Kathleen H. Claffy Assistant Examiner-Tom DAmico Attorney-Woodhams, Blanchard and Flynn ABSTRACT: In a telephone dialing device the punched card is not driven through a chute but is dropped through a substantially vertical chute. An electromagnetically operated plunger intermittently arrests the card in the chute, causing the card to drop through the chute in a series of steps. Photoelectric cells sense successive rows of holes in the card as the card drops in successive steps through the chute to control the transmission of dialing code signals.

PATENTED JUL 1 3 I97! SHEET 1 BF 2 CARD TELEPHONE DIALING MACHINE This invention relates to a telephone dialling device of the type in which a punched card on which a dialling code is stored is fed through a chute, the patterns of holes in a succession of rows on the card being sensed to control the transmission of dialling code signals. A known device of this nature drives the card through the chute and sensed the holes electromechanically. This leads to a mechanically complex, and hence expensive structure requiring an appreciable amount of maintenance.

The object of this invention is to provide an improved device requiring very few moving parts and in which any necessary complexity can be built into electronic circuitry, not mechanical parts.

According to the invention there is provided a telephone dialling device comprising a substantially vertical chute through which a punched card can be dropped, an electromagnetically operated plunger for arresting the card in the chute, means for intermittently operating the plunger to cause the card to drop through the chute in a series of steps, and means for sensing successive rows of holes in the card as the card drops in successive steps through the chute to control the transmission of dialling code signals.

The sensing means are preferably photoelectric cells, e.g. photoresistors. The plunger preferably engages in a succession of apertures or notches in the card.

The invention will be described in more detail, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is an isometric view, partly broken away of the chute of the device with a card therein, and

FIG. 2 is a block circuit diagram.

In FIG. 1 a vertical chute 10 for a punched card 12 is supported on a main frame 14 to which are also attached printed circuit boards (not shown) and all other electric components. This whole structure is enclosed within a moulded housing (also not shown) which has a slot in the top for the card to drop into the chute, a slot in the bottom of an overhanging front part for the card to drop out of the chute and a recess in the top behind the slot for storing a stack of cards.

An electromagnet 16 is mounted on the back of the frame 14 and its armature 18 can project a plunger 20 into the chute in the path of a column of holes 22 in the card against the action of a compression spring 24. Unless the device is switched on the plunger is withdrawn and a card drops straight through the chute. When the device is switched on the normal condition of the electromagnet is energized and therefore, when a card is dropped in, it will be arrested with its bottom edge on the plunger 20, in which position the bottom row R1 of 16 rows R1 to R16 of hole positions is aligned with a row of five photoelectric cells of which four cells 26 are shown in FIG. 1. These four cells are aligned with columns C1 to C4 of hole positions for storing in each row in accordance with a binary code one decimal digit ofa dialling code. A fifth column C is provided for indicating when an increased delay is required before transmitting the next dialling digit in order to meet the special requirements for some codes. The cell 28 for the" column C5 is shown only in FIG. 2.

The card 12 is preferably made of tough plastics material about 1 mm. thick with the holes 22 prepunched but with the other hole positions merely part punched through to permit the holes to be pushed out at the required positions in each row. A matt panel 34 is provided for writing on the nameof the subscriber identified by the card.

Another cell 30, lower than the cells 26 and 28 by the row to row pitch senses the presence of a card and starts the sequence of operations as later described. All the cells 26, 28 and 30 are mounted in a block 32 on the front of the chute. Behind the chute is a lamp (not shown) for illuminating the cells, preferably with light guides extending to positions op.- .posite the individual cells.

The columns C1 to C5 and the corresponding cells are asymmetrically disposed with respect to the vertical centerline of the card. If the card is inserted any way round other than the correct way all cells are obscured and the electrical circuits are arranged, as later described, to respond to this condition to deenergize the electromagnet 16 for long enough for the card to drop right out of the chute. This also means that when, as will usually be the case, the dialling code has less than 16 decimal digits, the first row with no holes punched out to come into line with the cells will cause the card to drop out of the chute without further delay.

Normally however, once the code for one row has been transmitted the electromagnet is deenergized for only 20 ms. which is the time taken for the card to drop from an initial position with the plunger 20 abutting the top edge of one hole 22 to a position with the plunger centered in the next hole above. The holes 22 are substantially larger than the plunger and the time taken to drop from the said initial position to a position with plunger abutting the top edge of the next hole above is 29 ms. This gives adequate tolerance allowing for small variations in dropping times caused by frictional forces.

Considerable variety is possible regarding the logic of the circuits controlling electromagnetic 16 and the transmission of dialling code signals. The circuit now to be described with reference to P16. 2 illustrates one mode of control when impulse dialling is employed. The invention is of course equally applicable to tone dialling and indeed the circuits will then be simpler. The cells 26 are then merely required to control the gating of the various tone combinations, via a suitable matrix assuming the dialling tone code to differ from the punched hole code. 7

Referring then to FIG. 2, showing a circuit made up of conventional blocks which can best be engineered using transistors, voltages which can and cannot operate gates will be denoted 1 and 0 respectively. The electromagnet 16 is normally energized from the HT. line 36 so as to arrest a card dropped in the chute. The card obscures the cell 30 whose output goes to 0 causing the outputs of NOR gates 38 and 40 to go to 1 and 0 respectively. The NOR gate 40 thus removes the clamp on a dialling pulse generator 42 through an OR gate 44 and also causes the output of a NOR gate 46 to go to 1. This output constitutes a switched H.T. line 48 and the appearance of H.T. on this line energizes a relay 50 whose contacts (not shown) connect the dialling device to line and mask dialling pulses in the manner of the off-normal contacts of a conventional dial.

The l on line 48 also fires a one-shot multivibrator 52 through an OR gate 54 and a capacitor 56. This one-shot is used to generate a pause before each decimal digit is dialled out and, when fired, it puts the clamp back on the pulse generator 42 through the OR gate 44. The output of the oneshot 52 also closes an AND gate 58 through a capacitor 60. Normally this deenergizes the electromagnet 16 through an OR gate 62 and a NOR gate 64 for the above-mentioned 20 ms., determined by the time constant of the capacitor 60 and AND gate 58. On this initial occasion however this is prevented by a connection from the switched H.T. line 48 (which has just gone to 1 through a capacitor 66 to the OR gate 62 which holds the output of the NOR gate 64 at 1". The time constant of the capacitor 66 and NOR gate 64 is made about four times that of capacitor 60 and AND gate 58.

The period of the one-shot 52 is 850 ms. and when it relaxes to the normal state the pulse generator 42 is unclamped and the output of a NOR gate 68 goes to l This puts a bright up voltage on the four cells 26 through a capacitor 70 and those cells which are illuminated go to low resistance and set 'the corresponding ones .of four bistables 72, 73, 74 and 75.

These four bistables are connected to operate as a binary counter of capacity 16 and the punched code used isthe complement with respect to 16 of the decimal dialling digit, i.e.

Digit: Code 4 s XXOO 5 ooxo 6 N XOXO 7 OXXO S XXXO 9 OOOX 0 (=10) OXOX NOTE! O=Punched hole; X=Unpunched hole.

This arrangement allows the bistables to be set from one side only, i.e. only four cells 26 are needed, without propagating spurious carries when setting.

The unclamped pulse generator now runs and transmits dialling pulses via a relay 78 and also applies pulses to the counter bistable 72 to count the counter back to its standby state, whereupon all inputs to a NOR gate 80 are 0 and this gate again fires the one shot 52 to clamp the pulse generator 42. On this occasion the electromagnet 16 is deenergized for the 20 ms. interval and the card drops to the second row. The sequence of operations repeats cyclically until a row is reached with no holes punched out. The bistables 72 to 75 then all remain unset and therefore an AND gate 82 receives simultaneous l s from the NOR gate 80 and a capacitor 84 connected to the output ofa NOR gate 86 whose input is connected to the capacitor 70. The AND gate 82 thereupon sets a number sent" bistable 88. This bistable then clamps the generator 42 through the gate 44 and also puts a 0" on the AND gate 58 which deenergizes the electromagnet 16. The card 12 then drops out of the chute since the bistable 88 is not reset until the switched H.T. on line 48 is removed, which does not take place until the cell is reilluminated.

it will be appreciated that the bistable 88 will also be set if the card is put in the chute the wrong way round and a pushbutton switch 90 for setting the bistable is provided for the user to cancel a call if he wishes to do so while the card is in the chute.

The bistables 72 to 75 have one-half fed from the line 48 to ensure that they are in the standby state before the first row is read. The bistable 72 is driven from the side of the generator 42 (a free running multivibrator) which is 0 when the generator is clamped to delay the steering of the counter by 66ms., assuming the pulse generator to operate with the conventional 66/33 ms. period.

When a hole in column CS is punched out to cause a long delay before sending the next digit the cell 28 is illuminated. This causes the period of the one-shot 52 to be lengthened to 1.9 seconds.

For compactness the electronic circuits can be fabricated as MOS integrated circuits: The device can also incorporate additional facilities, well-known in themselves. For example a loudspeaker can be built in to enable the caller to hear when the called party answers and thus when to lift his handset. Al-

ternatively both microphone and loudspeaker can be built in to allow the caller to converse without lifting his handset.

What I claim is:

l. A telephone dialling device for use with a punched dialling card comprising a substantially vertical chute constructed and arranged to have said card dropped therethrough, an electromagnetically operated plunger for arresting said card in said chute, means for intermittently operating said plunger to cause said card to drop through said chute in a series of steps, and means for sensing successive rows of holes in said card as the card drops in successive steps through said chute to control the transmission of dialling code signals.

2. A device according to claim ll, wherein said sensing means comprise a plurality of photoelectric cells.

3. A device according to claim 1, wherein said plunger is normally positioned to arrest said card and comprising further sensing means arranged to sense the presence of a card arrested in said chute and to initiate a sequence of operations in which said plunger is intermittently retracted to cause said card to drop in the said series of steps.

4. A device according to claim 3, comprising circuit means responsive to sensing a row in which no holes are punched out to cause said plunger to be retracted long enough or said card to drop completely out of said chute.

5. A device according to claim 4, wherein said first-mentioned sensing means are positioned for sensing holes arranged in asymmetrically disposed columns, such that insertion of a card in said chute other than the correct way round causes a row in which no holes are punched out to be sensed immediately to cause said card to drop out of said chute.

6. A device according to claim 1, in combination with a card having a column of cut out portions adapted to cooperate with said plunger to arrest the card with successive rows of holes aligned with said sensing means.

7. A combination according to claim 6, wherein said cutout portions are holes.

8. A telephone dialling device for use with a punched dialling card comprising a substantially vertical chute constructed and arranged to have said card dropped therethrough, an electromagnetically operated plunger for arresting said card in said chute, means for intermittently operating said plunger to cause said card to drop through said chute in a series of steps, means for sensing successive rows of holes in said card as the card drops in successive steps through said chute to control the transmission of dialling code signals, and a binary counter having a plurality of stages corresponding to columns of holes respectively, said sensing means being arranged to set each stage in accordance with whether a hole is or is not punched out in the corresponding column, and means for applying pulses to restore said counter to a datum state and for simultaneously emitting dialling pulses.

9. A device according to claim 8, wherein said counter has four stages for setting to the complement with respect to 16 of the digit to be dialled and wherein the pulses applied to said counter count the counter up to 16. 

1. A telephone dialling device for use with a punched dialling card comprising a substantially vertical chute constructed and arranged to have said card dropped therethrough, an electromagnetically operated plunger for arresting said card in said chute, means for intermittently operating said plunger to cause said card to drop through said chute in a series of steps, and means for sensing successive rows of holes in said card as the card drops in successive steps through said chute to control the transmission of dialling code signals.
 2. A device according to claim 1, wherein said sensing means comprise a plurality of photoelectric cells.
 3. A device according to claim 1, wherein said plunger is normally positioned to arrest said card and comprising further sensing means arranged to sense the presence of a card arrested in said chute and to initiate a sequence of operations in which said plunger is intermittently retracted to cause said card to drop in the said series of steps.
 4. A device according to claim 3, comprising circuit means responsive to sensing a row in which no holes are punched out to cause said plunger to be retracted long enough for said card to drop completely out of said chute.
 5. A device according to claim 4, wherein said first-mentioned sensing means are positioned for sensing holes arranged in asymmetrically disposed columns, such that insertion of a card in said chute other than the correct way round causes a row in which no holes are punched out to be sensed immediately to cause said card to drop out of said chute.
 6. A device according to claim 1, in combination with a card having a column of cut out portions adapted to cooperate with said plunger to arrest the card with successive rows of holes aligned with said sensing means.
 7. A combination according to claim 6, wherein said cutout portions are holes.
 8. A telephone dialling device for use with a punched dialling card comprising a substantially vertical chute constructed and arranged to have said card dropped therethrough, an electromagnetically operated plunger for arresting said card in said chute, means for intermittently operating said plunger to cause said card to drop through said chute in a series of steps, means for sensing successive rows of holes in said card as the card drops in successive steps through said chute to control the transmission of dialling code signals, and a binary counter having a plurality of stages corresponding to columns of holes respectively, said sensing means being arranged to set each stage in accordance with whether a hole is or is not punched out in the corresponding column, and means for applying pulses to restore said counter to a datum state and for simultaneously emitting dialling pulses.
 9. A device according to claim 8, wherein said counter has four stages for setting to the complement with respect to 16 of the digit to be dialled and wherein the pulses applied to said counter count the counter up to
 16. 